diff --git a/src/net.cpp b/src/net.cpp index e989b4e3c..d13795dcf 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -1,3314 +1,3343 @@ // Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2009-2019 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. #if defined(HAVE_CONFIG_H) #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef WIN32 #include #else #include #endif #ifdef USE_POLL #include #endif #ifdef USE_UPNP #include #include #include // The minimum supported miniUPnPc API version is set to 10. This keeps // compatibility with Ubuntu 16.04 LTS and Debian 8 libminiupnpc-dev packages. static_assert(MINIUPNPC_API_VERSION >= 10, "miniUPnPc API version >= 10 assumed"); #endif #include #include #include #include #include #include // How often to dump addresses to peers.dat static constexpr std::chrono::minutes DUMP_PEERS_INTERVAL{15}; /** * Number of DNS seeds to query when the number of connections is low. */ static constexpr int DNSSEEDS_TO_QUERY_AT_ONCE = 3; /** * How long to delay before querying DNS seeds * * If we have more than THRESHOLD entries in addrman, then it's likely * that we got those addresses from having previously connected to the P2P * network, and that we'll be able to successfully reconnect to the P2P * network via contacting one of them. So if that's the case, spend a * little longer trying to connect to known peers before querying the * DNS seeds. */ static constexpr std::chrono::seconds DNSSEEDS_DELAY_FEW_PEERS{11}; static constexpr std::chrono::minutes DNSSEEDS_DELAY_MANY_PEERS{5}; // "many" vs "few" peers static constexpr int DNSSEEDS_DELAY_PEER_THRESHOLD = 1000; // We add a random period time (0 to 1 seconds) to feeler connections to prevent // synchronization. #define FEELER_SLEEP_WINDOW 1 // MSG_NOSIGNAL is not available on some platforms, if it doesn't exist define // it as 0 #if !defined(MSG_NOSIGNAL) #define MSG_NOSIGNAL 0 #endif // MSG_DONTWAIT is not available on some platforms, if it doesn't exist define // it as 0 #if !defined(MSG_DONTWAIT) #define MSG_DONTWAIT 0 #endif /** Used to pass flags to the Bind() function */ enum BindFlags { BF_NONE = 0, BF_EXPLICIT = (1U << 0), BF_REPORT_ERROR = (1U << 1), }; // The set of sockets cannot be modified while waiting // The sleep time needs to be small to avoid new sockets stalling static const uint64_t SELECT_TIMEOUT_MILLISECONDS = 50; const std::string NET_MESSAGE_COMMAND_OTHER = "*other*"; // SHA256("netgroup")[0:8] static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL; // SHA256("localhostnonce")[0:8] static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL; // SHA256("localhostnonce")[8:16] static const uint64_t RANDOMIZER_ID_EXTRAENTROPY = 0x94b05d41679a4ff7ULL; // // Global state variables // bool fDiscover = true; bool fListen = true; bool g_relay_txes = !DEFAULT_BLOCKSONLY; RecursiveMutex cs_mapLocalHost; std::map mapLocalHost GUARDED_BY(cs_mapLocalHost); static bool vfLimited[NET_MAX] GUARDED_BY(cs_mapLocalHost) = {}; void CConnman::AddAddrFetch(const std::string &strDest) { LOCK(m_addr_fetches_mutex); m_addr_fetches.push_back(strDest); } uint16_t GetListenPort() { return uint16_t(gArgs.GetArg("-port", Params().GetDefaultPort())); } // find 'best' local address for a particular peer bool GetLocal(CService &addr, const CNetAddr *paddrPeer) { if (!fListen) { return false; } int nBestScore = -1; int nBestReachability = -1; { LOCK(cs_mapLocalHost); for (const auto &entry : mapLocalHost) { int nScore = entry.second.nScore; int nReachability = entry.first.GetReachabilityFrom(paddrPeer); if (nReachability > nBestReachability || (nReachability == nBestReachability && nScore > nBestScore)) { addr = CService(entry.first, entry.second.nPort); nBestReachability = nReachability; nBestScore = nScore; } } } return nBestScore >= 0; } //! Convert the pnSeed6 array into usable address objects. static std::vector convertSeed6(const std::vector &vSeedsIn) { // It'll only connect to one or two seed nodes because once it connects, // it'll get a pile of addresses with newer timestamps. Seed nodes are given // a random 'last seen time' of between one and two weeks ago. const int64_t nOneWeek = 7 * 24 * 60 * 60; std::vector vSeedsOut; vSeedsOut.reserve(vSeedsIn.size()); FastRandomContext rng; for (const auto &seed_in : vSeedsIn) { struct in6_addr ip; memcpy(&ip, seed_in.addr, sizeof(ip)); CAddress addr(CService(ip, seed_in.port), GetDesirableServiceFlags(NODE_NONE)); addr.nTime = GetTime() - rng.randrange(nOneWeek) - nOneWeek; vSeedsOut.push_back(addr); } return vSeedsOut; } // Get best local address for a particular peer as a CAddress. Otherwise, return // the unroutable 0.0.0.0 but filled in with the normal parameters, since the IP // may be changed to a useful one by discovery. CAddress GetLocalAddress(const CNetAddr *paddrPeer, ServiceFlags nLocalServices) { CAddress ret(CService(CNetAddr(), GetListenPort()), nLocalServices); CService addr; if (GetLocal(addr, paddrPeer)) { ret = CAddress(addr, nLocalServices); } ret.nTime = GetAdjustedTime(); return ret; } static int GetnScore(const CService &addr) { LOCK(cs_mapLocalHost); if (mapLocalHost.count(addr) == 0) { return 0; } return mapLocalHost[addr].nScore; } // Is our peer's addrLocal potentially useful as an external IP source? bool IsPeerAddrLocalGood(CNode *pnode) { CService addrLocal = pnode->GetAddrLocal(); return fDiscover && pnode->addr.IsRoutable() && addrLocal.IsRoutable() && IsReachable(addrLocal.GetNetwork()); } // Pushes our own address to a peer. void AdvertiseLocal(CNode *pnode) { if (fListen && pnode->fSuccessfullyConnected) { CAddress addrLocal = GetLocalAddress(&pnode->addr, pnode->GetLocalServices()); if (gArgs.GetBoolArg("-addrmantest", false)) { // use IPv4 loopback during addrmantest addrLocal = CAddress(CService(LookupNumeric("127.0.0.1", GetListenPort())), pnode->GetLocalServices()); } // If discovery is enabled, sometimes give our peer the address it // tells us that it sees us as in case it has a better idea of our // address than we do. FastRandomContext rng; if (IsPeerAddrLocalGood(pnode) && (!addrLocal.IsRoutable() || rng.randbits((GetnScore(addrLocal) > LOCAL_MANUAL) ? 3 : 1) == 0)) { addrLocal.SetIP(pnode->GetAddrLocal()); } if (addrLocal.IsRoutable() || gArgs.GetBoolArg("-addrmantest", false)) { LogPrint(BCLog::NET, "AdvertiseLocal: advertising address %s\n", addrLocal.ToString()); pnode->PushAddress(addrLocal, rng); } } } // Learn a new local address. bool AddLocal(const CService &addr, int nScore) { if (!addr.IsRoutable()) { return false; } if (!fDiscover && nScore < LOCAL_MANUAL) { return false; } if (!IsReachable(addr)) { return false; } LogPrintf("AddLocal(%s,%i)\n", addr.ToString(), nScore); { LOCK(cs_mapLocalHost); bool fAlready = mapLocalHost.count(addr) > 0; LocalServiceInfo &info = mapLocalHost[addr]; if (!fAlready || nScore >= info.nScore) { info.nScore = nScore + (fAlready ? 1 : 0); info.nPort = addr.GetPort(); } } return true; } bool AddLocal(const CNetAddr &addr, int nScore) { return AddLocal(CService(addr, GetListenPort()), nScore); } void RemoveLocal(const CService &addr) { LOCK(cs_mapLocalHost); LogPrintf("RemoveLocal(%s)\n", addr.ToString()); mapLocalHost.erase(addr); } void SetReachable(enum Network net, bool reachable) { if (net == NET_UNROUTABLE || net == NET_INTERNAL) { return; } LOCK(cs_mapLocalHost); vfLimited[net] = !reachable; } bool IsReachable(enum Network net) { LOCK(cs_mapLocalHost); return !vfLimited[net]; } bool IsReachable(const CNetAddr &addr) { return IsReachable(addr.GetNetwork()); } /** vote for a local address */ bool SeenLocal(const CService &addr) { LOCK(cs_mapLocalHost); if (mapLocalHost.count(addr) == 0) { return false; } mapLocalHost[addr].nScore++; return true; } /** check whether a given address is potentially local */ bool IsLocal(const CService &addr) { LOCK(cs_mapLocalHost); return mapLocalHost.count(addr) > 0; } CNode *CConnman::FindNode(const CNetAddr &ip) { LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (static_cast(pnode->addr) == ip) { return pnode; } } return nullptr; } CNode *CConnman::FindNode(const CSubNet &subNet) { LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (subNet.Match(static_cast(pnode->addr))) { return pnode; } } return nullptr; } CNode *CConnman::FindNode(const std::string &addrName) { LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (pnode->GetAddrName() == addrName) { return pnode; } } return nullptr; } CNode *CConnman::FindNode(const CService &addr) { LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (static_cast(pnode->addr) == addr) { return pnode; } } return nullptr; } bool CConnman::CheckIncomingNonce(uint64_t nonce) { LOCK(cs_vNodes); for (const CNode *pnode : vNodes) { if (!pnode->fSuccessfullyConnected && !pnode->IsInboundConn() && pnode->GetLocalNonce() == nonce) { return false; } } return true; } /** Get the bind address for a socket as CAddress */ static CAddress GetBindAddress(SOCKET sock) { CAddress addr_bind; struct sockaddr_storage sockaddr_bind; socklen_t sockaddr_bind_len = sizeof(sockaddr_bind); if (sock != INVALID_SOCKET) { if (!getsockname(sock, (struct sockaddr *)&sockaddr_bind, &sockaddr_bind_len)) { addr_bind.SetSockAddr((const struct sockaddr *)&sockaddr_bind); } else { LogPrint(BCLog::NET, "Warning: getsockname failed\n"); } } return addr_bind; } CNode *CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure, ConnectionType conn_type) { assert(conn_type != ConnectionType::INBOUND); if (pszDest == nullptr) { if (IsLocal(addrConnect)) { return nullptr; } // Look for an existing connection CNode *pnode = FindNode(static_cast(addrConnect)); if (pnode) { LogPrintf("Failed to open new connection, already connected\n"); return nullptr; } } /// debug print LogPrint(BCLog::NET, "trying connection %s lastseen=%.1fhrs\n", pszDest ? pszDest : addrConnect.ToString(), pszDest ? 0.0 : (double)(GetAdjustedTime() - addrConnect.nTime) / 3600.0); // Resolve const int default_port = Params().GetDefaultPort(); if (pszDest) { std::vector resolved; if (Lookup(pszDest, resolved, default_port, fNameLookup && !HaveNameProxy(), 256) && !resolved.empty()) { addrConnect = CAddress(resolved[GetRand(resolved.size())], NODE_NONE); if (!addrConnect.IsValid()) { LogPrint(BCLog::NET, "Resolver returned invalid address %s for %s\n", addrConnect.ToString(), pszDest); return nullptr; } // It is possible that we already have a connection to the IP/port // pszDest resolved to. In that case, drop the connection that was // just created, and return the existing CNode instead. Also store // the name we used to connect in that CNode, so that future // FindNode() calls to that name catch this early. LOCK(cs_vNodes); CNode *pnode = FindNode(static_cast(addrConnect)); if (pnode) { pnode->MaybeSetAddrName(std::string(pszDest)); LogPrintf("Failed to open new connection, already connected\n"); return nullptr; } } } // Connect bool connected = false; SOCKET hSocket = INVALID_SOCKET; proxyType proxy; if (addrConnect.IsValid()) { bool proxyConnectionFailed = false; if (GetProxy(addrConnect.GetNetwork(), proxy)) { hSocket = CreateSocket(proxy.proxy); if (hSocket == INVALID_SOCKET) { return nullptr; } connected = ConnectThroughProxy( proxy, addrConnect.ToStringIP(), addrConnect.GetPort(), hSocket, nConnectTimeout, proxyConnectionFailed); } else { // no proxy needed (none set for target network) hSocket = CreateSocket(addrConnect); if (hSocket == INVALID_SOCKET) { return nullptr; } connected = ConnectSocketDirectly(addrConnect, hSocket, nConnectTimeout, conn_type == ConnectionType::MANUAL); } if (!proxyConnectionFailed) { // If a connection to the node was attempted, and failure (if any) // is not caused by a problem connecting to the proxy, mark this as // an attempt. addrman.Attempt(addrConnect, fCountFailure); } } else if (pszDest && GetNameProxy(proxy)) { hSocket = CreateSocket(proxy.proxy); if (hSocket == INVALID_SOCKET) { return nullptr; } std::string host; int port = default_port; SplitHostPort(std::string(pszDest), port, host); bool proxyConnectionFailed; connected = ConnectThroughProxy(proxy, host, port, hSocket, nConnectTimeout, proxyConnectionFailed); } if (!connected) { CloseSocket(hSocket); return nullptr; } // Add node NodeId id = GetNewNodeId(); uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE) .Write(id) .Finalize(); uint64_t extra_entropy = GetDeterministicRandomizer(RANDOMIZER_ID_EXTRAENTROPY) .Write(id) .Finalize(); CAddress addr_bind = GetBindAddress(hSocket); CNode *pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, extra_entropy, addr_bind, pszDest ? pszDest : "", conn_type); pnode->AddRef(); // We're making a new connection, harvest entropy from the time (and our // peer count) RandAddEvent(uint32_t(id)); return pnode; } void CNode::CloseSocketDisconnect() { fDisconnect = true; LOCK(cs_hSocket); if (hSocket != INVALID_SOCKET) { LogPrint(BCLog::NET, "disconnecting peer=%d\n", id); CloseSocket(hSocket); } } void CConnman::AddWhitelistPermissionFlags(NetPermissionFlags &flags, const CNetAddr &addr) const { for (const auto &subnet : vWhitelistedRange) { if (subnet.m_subnet.Match(addr)) { NetPermissions::AddFlag(flags, subnet.m_flags); } } } std::string CNode::GetAddrName() const { LOCK(cs_addrName); return addrName; } void CNode::MaybeSetAddrName(const std::string &addrNameIn) { LOCK(cs_addrName); if (addrName.empty()) { addrName = addrNameIn; } } CService CNode::GetAddrLocal() const { LOCK(cs_addrLocal); return addrLocal; } void CNode::SetAddrLocal(const CService &addrLocalIn) { LOCK(cs_addrLocal); if (addrLocal.IsValid()) { error("Addr local already set for node: %i. Refusing to change from %s " "to %s", id, addrLocal.ToString(), addrLocalIn.ToString()); } else { addrLocal = addrLocalIn; } } void CNode::copyStats(CNodeStats &stats, const std::vector &m_asmap) { stats.nodeid = this->GetId(); stats.nServices = nServices; stats.addr = addr; stats.addrBind = addrBind; stats.m_mapped_as = addr.GetMappedAS(m_asmap); if (m_tx_relay != nullptr) { LOCK(m_tx_relay->cs_filter); stats.fRelayTxes = m_tx_relay->fRelayTxes; } else { stats.fRelayTxes = false; } stats.nLastSend = nLastSend; stats.nLastRecv = nLastRecv; stats.nLastTXTime = nLastTXTime; stats.nLastProofTime = nLastProofTime; stats.nLastBlockTime = nLastBlockTime; stats.nTimeConnected = nTimeConnected; stats.nTimeOffset = nTimeOffset; stats.addrName = GetAddrName(); stats.nVersion = nVersion; { LOCK(cs_SubVer); stats.cleanSubVer = cleanSubVer; } stats.fInbound = IsInboundConn(); stats.m_manual_connection = IsManualConn(); stats.nStartingHeight = nStartingHeight; { LOCK(cs_vSend); stats.mapSendBytesPerMsgCmd = mapSendBytesPerMsgCmd; stats.nSendBytes = nSendBytes; } { LOCK(cs_vRecv); stats.mapRecvBytesPerMsgCmd = mapRecvBytesPerMsgCmd; stats.nRecvBytes = nRecvBytes; } stats.m_legacyWhitelisted = m_legacyWhitelisted; stats.m_permissionFlags = m_permissionFlags; if (m_tx_relay != nullptr) { LOCK(m_tx_relay->cs_feeFilter); stats.minFeeFilter = m_tx_relay->minFeeFilter; } else { stats.minFeeFilter = Amount::zero(); } // It is common for nodes with good ping times to suddenly become lagged, // due to a new block arriving or other large transfer. Merely reporting // pingtime might fool the caller into thinking the node was still // responsive, since pingtime does not update until the ping is complete, // which might take a while. So, if a ping is taking an unusually long time // in flight, the caller can immediately detect that this is happening. std::chrono::microseconds ping_wait{0}; if ((0 != nPingNonceSent) && (0 != m_ping_start.load().count())) { ping_wait = GetTime() - m_ping_start.load(); } // Raw ping time is in microseconds, but show it to user as whole seconds // (Bitcoin users should be well used to small numbers with many decimal // places by now :) stats.m_ping_usec = nPingUsecTime; stats.m_min_ping_usec = nMinPingUsecTime; stats.m_ping_wait_usec = count_microseconds(ping_wait); // Leave string empty if addrLocal invalid (not filled in yet) CService addrLocalUnlocked = GetAddrLocal(); stats.addrLocal = addrLocalUnlocked.IsValid() ? addrLocalUnlocked.ToString() : ""; } bool CNode::ReceiveMsgBytes(const Config &config, const char *pch, uint32_t nBytes, bool &complete) { complete = false; const auto time = GetTime(); LOCK(cs_vRecv); nLastRecv = std::chrono::duration_cast(time).count(); nRecvBytes += nBytes; while (nBytes > 0) { // Absorb network data. int handled = m_deserializer->Read(config, pch, nBytes); if (handled < 0) { return false; } pch += handled; nBytes -= handled; if (m_deserializer->Complete()) { // decompose a transport agnostic CNetMessage from the deserializer CNetMessage msg = m_deserializer->GetMessage(config, time); // Store received bytes per message command to prevent a memory DOS, // only allow valid commands. mapMsgCmdSize::iterator i = mapRecvBytesPerMsgCmd.find(msg.m_command); if (i == mapRecvBytesPerMsgCmd.end()) { i = mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER); } assert(i != mapRecvBytesPerMsgCmd.end()); i->second += msg.m_raw_message_size; // push the message to the process queue, vRecvMsg.push_back(std::move(msg)); complete = true; } } return true; } int V1TransportDeserializer::readHeader(const Config &config, const char *pch, uint32_t nBytes) { // copy data to temporary parsing buffer uint32_t nRemaining = CMessageHeader::HEADER_SIZE - nHdrPos; uint32_t nCopy = std::min(nRemaining, nBytes); memcpy(&hdrbuf[nHdrPos], pch, nCopy); nHdrPos += nCopy; // if header incomplete, exit if (nHdrPos < CMessageHeader::HEADER_SIZE) { return nCopy; } // deserialize to CMessageHeader try { hdrbuf >> hdr; } catch (const std::exception &) { return -1; } // Reject oversized messages if (hdr.IsOversized(config)) { LogPrint(BCLog::NET, "Oversized header detected\n"); return -1; } // switch state to reading message data in_data = true; return nCopy; } int V1TransportDeserializer::readData(const char *pch, uint32_t nBytes) { unsigned int nRemaining = hdr.nMessageSize - nDataPos; unsigned int nCopy = std::min(nRemaining, nBytes); if (vRecv.size() < nDataPos + nCopy) { // Allocate up to 256 KiB ahead, but never more than the total message // size. vRecv.resize(std::min(hdr.nMessageSize, nDataPos + nCopy + 256 * 1024)); } hasher.Write({(const uint8_t *)pch, nCopy}); memcpy(&vRecv[nDataPos], pch, nCopy); nDataPos += nCopy; return nCopy; } const uint256 &V1TransportDeserializer::GetMessageHash() const { assert(Complete()); if (data_hash.IsNull()) { hasher.Finalize(data_hash); } return data_hash; } CNetMessage V1TransportDeserializer::GetMessage(const Config &config, const std::chrono::microseconds time) { // decompose a single CNetMessage from the TransportDeserializer CNetMessage msg(std::move(vRecv)); // store state about valid header, netmagic and checksum msg.m_valid_header = hdr.IsValid(config); // FIXME Split CheckHeaderMagicAndCommand() into CheckHeaderMagic() and // CheckCommand() to prevent the net magic check code duplication. msg.m_valid_netmagic = (memcmp(std::begin(hdr.pchMessageStart), std::begin(config.GetChainParams().NetMagic()), CMessageHeader::MESSAGE_START_SIZE) == 0); uint256 hash = GetMessageHash(); // store command string, payload size msg.m_command = hdr.GetCommand(); msg.m_message_size = hdr.nMessageSize; msg.m_raw_message_size = hdr.nMessageSize + CMessageHeader::HEADER_SIZE; // We just received a message off the wire, harvest entropy from the time // (and the message checksum) RandAddEvent(ReadLE32(hash.begin())); msg.m_valid_checksum = (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) == 0); if (!msg.m_valid_checksum) { LogPrint( BCLog::NET, "CHECKSUM ERROR (%s, %u bytes), expected %s was %s\n", SanitizeString(msg.m_command), msg.m_message_size, HexStr(Span(hash.begin(), hash.begin() + CMessageHeader::CHECKSUM_SIZE)), HexStr(hdr.pchChecksum)); } // store receive time msg.m_time = time; // reset the network deserializer (prepare for the next message) Reset(); return msg; } void V1TransportSerializer::prepareForTransport(const Config &config, CSerializedNetMsg &msg, std::vector &header) { // create dbl-sha256 checksum uint256 hash = Hash(msg.data); // create header CMessageHeader hdr(config.GetChainParams().NetMagic(), msg.m_type.c_str(), msg.data.size()); memcpy(hdr.pchChecksum, hash.begin(), CMessageHeader::CHECKSUM_SIZE); // serialize header header.reserve(CMessageHeader::HEADER_SIZE); CVectorWriter{SER_NETWORK, INIT_PROTO_VERSION, header, 0, hdr}; } size_t CConnman::SocketSendData(CNode *pnode) const EXCLUSIVE_LOCKS_REQUIRED(pnode->cs_vSend) { size_t nSentSize = 0; size_t nMsgCount = 0; for (const auto &data : pnode->vSendMsg) { assert(data.size() > pnode->nSendOffset); int nBytes = 0; { LOCK(pnode->cs_hSocket); if (pnode->hSocket == INVALID_SOCKET) { break; } nBytes = send(pnode->hSocket, reinterpret_cast(data.data()) + pnode->nSendOffset, data.size() - pnode->nSendOffset, MSG_NOSIGNAL | MSG_DONTWAIT); } if (nBytes == 0) { // couldn't send anything at all break; } if (nBytes < 0) { // error int nErr = WSAGetLastError(); if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS) { LogPrintf("socket send error %s\n", NetworkErrorString(nErr)); pnode->CloseSocketDisconnect(); } break; } assert(nBytes > 0); pnode->nLastSend = GetSystemTimeInSeconds(); pnode->nSendBytes += nBytes; pnode->nSendOffset += nBytes; nSentSize += nBytes; if (pnode->nSendOffset != data.size()) { // could not send full message; stop sending more break; } pnode->nSendOffset = 0; pnode->nSendSize -= data.size(); pnode->fPauseSend = pnode->nSendSize > nSendBufferMaxSize; nMsgCount++; } pnode->vSendMsg.erase(pnode->vSendMsg.begin(), pnode->vSendMsg.begin() + nMsgCount); if (pnode->vSendMsg.empty()) { assert(pnode->nSendOffset == 0); assert(pnode->nSendSize == 0); } return nSentSize; } static bool ReverseCompareNodeMinPingTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { return a.nMinPingUsecTime > b.nMinPingUsecTime; } static bool ReverseCompareNodeTimeConnected(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { return a.nTimeConnected > b.nTimeConnected; } static bool CompareLocalHostTimeConnected(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { if (a.m_is_local != b.m_is_local) { return b.m_is_local; } return a.nTimeConnected > b.nTimeConnected; } static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { return a.nKeyedNetGroup < b.nKeyedNetGroup; } static bool CompareNodeBlockTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { // There is a fall-through here because it is common for a node to have many // peers which have not yet relayed a block. if (a.nLastBlockTime != b.nLastBlockTime) { return a.nLastBlockTime < b.nLastBlockTime; } if (a.fRelevantServices != b.fRelevantServices) { return b.fRelevantServices; } return a.nTimeConnected > b.nTimeConnected; } static bool CompareNodeTXTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { // There is a fall-through here because it is common for a node to have more // than a few peers that have not yet relayed txn. if (a.nLastTXTime != b.nLastTXTime) { return a.nLastTXTime < b.nLastTXTime; } if (a.fRelayTxes != b.fRelayTxes) { return b.fRelayTxes; } if (a.fBloomFilter != b.fBloomFilter) { return a.fBloomFilter; } return a.nTimeConnected > b.nTimeConnected; } static bool CompareNodeProofTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { // There is a fall-through here because it is common for a node to have more // than a few peers that have not yet relayed proofs. This fallback is also // used in the case avalanche is not enabled. if (a.nLastProofTime != b.nLastProofTime) { return a.nLastProofTime < b.nLastProofTime; } return a.nTimeConnected > b.nTimeConnected; } // Pick out the potential block-relay only peers, and sort them by last block // time. static bool CompareNodeBlockRelayOnlyTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { if (a.fRelayTxes != b.fRelayTxes) { return a.fRelayTxes; } if (a.nLastBlockTime != b.nLastBlockTime) { return a.nLastBlockTime < b.nLastBlockTime; } if (a.fRelevantServices != b.fRelevantServices) { return b.fRelevantServices; } return a.nTimeConnected > b.nTimeConnected; } static bool CompareNodeAvailabilityScore(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { // Equality can happen if the nodes have no score or it has not been // computed yet. if (a.availabilityScore != b.availabilityScore) { return a.availabilityScore < b.availabilityScore; } return a.nTimeConnected > b.nTimeConnected; } //! Sort an array by the specified comparator, then erase the last K elements. template static void EraseLastKElements(std::vector &elements, Comparator comparator, size_t k) { std::sort(elements.begin(), elements.end(), comparator); size_t eraseSize = std::min(k, elements.size()); elements.erase(elements.end() - eraseSize, elements.end()); } //! Sort an array by the specified comparator, then erase up to K last elements //! which verify the condition. template static void EraseLastKElementsIf(std::vector &elements, Comparator comparator, size_t k, Condition cond) { std::sort(elements.begin(), elements.end(), comparator); size_t eraseSize = std::min(k, elements.size()); elements.erase( std::remove_if(elements.end() - eraseSize, elements.end(), cond), elements.end()); } [[nodiscard]] std::optional SelectNodeToEvict(std::vector &&vEvictionCandidates) { // Protect connections with certain characteristics // Deterministically select 4 peers to protect by netgroup. // An attacker cannot predict which netgroups will be protected EraseLastKElements(vEvictionCandidates, CompareNetGroupKeyed, 4); // Protect the 8 nodes with the lowest minimum ping time. // An attacker cannot manipulate this metric without physically moving nodes // closer to the target. EraseLastKElements(vEvictionCandidates, ReverseCompareNodeMinPingTime, 8); // Protect 4 nodes that most recently sent us novel transactions accepted // into our mempool. An attacker cannot manipulate this metric without // performing useful work. EraseLastKElements(vEvictionCandidates, CompareNodeTXTime, 4); // Protect 4 nodes that most recently sent us novel proofs accepted // into our proof pool. An attacker cannot manipulate this metric without // performing useful work. // TODO this filter must happen before the last tx time once avalanche is // enabled for pre-consensus. EraseLastKElements(vEvictionCandidates, CompareNodeProofTime, 4); // Protect up to 8 non-tx-relay peers that have sent us novel blocks. EraseLastKElementsIf(vEvictionCandidates, CompareNodeBlockRelayOnlyTime, 8, [](NodeEvictionCandidate const &n) { return !n.fRelayTxes && n.fRelevantServices; }); // Protect 4 nodes that most recently sent us novel blocks. // An attacker cannot manipulate this metric without performing useful work. EraseLastKElements(vEvictionCandidates, CompareNodeBlockTime, 4); // Protect up to 128 nodes that have the highest avalanche availability // score. EraseLastKElementsIf(vEvictionCandidates, CompareNodeAvailabilityScore, 128, [](NodeEvictionCandidate const &n) { return n.availabilityScore > 0.; }); // Protect the half of the remaining nodes which have been connected the // longest. This replicates the non-eviction implicit behavior, and // precludes attacks that start later. // Reserve half of these protected spots for localhost peers, even if // they're not longest-uptime overall. This helps protect tor peers, which // tend to be otherwise disadvantaged under our eviction criteria. size_t initial_size = vEvictionCandidates.size(); size_t total_protect_size = initial_size / 2; // Pick out up to 1/4 peers that are localhost, sorted by longest uptime. EraseLastKElementsIf( vEvictionCandidates, CompareLocalHostTimeConnected, total_protect_size / 2, [](NodeEvictionCandidate const &n) { return n.m_is_local; }); // Calculate how many we removed, and update our total number of peers that // we want to protect based on uptime accordingly. total_protect_size -= initial_size - vEvictionCandidates.size(); EraseLastKElements(vEvictionCandidates, ReverseCompareNodeTimeConnected, total_protect_size); if (vEvictionCandidates.empty()) { return std::nullopt; } // If any remaining peers are preferred for eviction consider only them. // This happens after the other preferences since if a peer is really the // best by other criteria (esp relaying blocks) // then we probably don't want to evict it no matter what. if (std::any_of( vEvictionCandidates.begin(), vEvictionCandidates.end(), [](NodeEvictionCandidate const &n) { return n.prefer_evict; })) { vEvictionCandidates.erase( std::remove_if( vEvictionCandidates.begin(), vEvictionCandidates.end(), [](NodeEvictionCandidate const &n) { return !n.prefer_evict; }), vEvictionCandidates.end()); } // Identify the network group with the most connections and youngest member. // (vEvictionCandidates is already sorted by reverse connect time) uint64_t naMostConnections; unsigned int nMostConnections = 0; int64_t nMostConnectionsTime = 0; std::map> mapNetGroupNodes; for (const NodeEvictionCandidate &node : vEvictionCandidates) { std::vector &group = mapNetGroupNodes[node.nKeyedNetGroup]; group.push_back(node); int64_t grouptime = group[0].nTimeConnected; size_t group_size = group.size(); if (group_size > nMostConnections || (group_size == nMostConnections && grouptime > nMostConnectionsTime)) { nMostConnections = group_size; nMostConnectionsTime = grouptime; naMostConnections = node.nKeyedNetGroup; } } // Reduce to the network group with the most connections vEvictionCandidates = std::move(mapNetGroupNodes[naMostConnections]); // Disconnect from the network group with the most connections return vEvictionCandidates.front().id; } /** Try to find a connection to evict when the node is full. * Extreme care must be taken to avoid opening the node to attacker * triggered network partitioning. * The strategy used here is to protect a small number of peers * for each of several distinct characteristics which are difficult * to forge. In order to partition a node the attacker must be * simultaneously better at all of them than honest peers. */ bool CConnman::AttemptToEvictConnection() { std::vector vEvictionCandidates; { LOCK(cs_vNodes); for (const CNode *node : vNodes) { if (node->HasPermission(PF_NOBAN)) { continue; } if (!node->IsInboundConn()) { continue; } if (node->fDisconnect) { continue; } bool peer_relay_txes = false; bool peer_filter_not_null = false; if (node->m_tx_relay != nullptr) { LOCK(node->m_tx_relay->cs_filter); peer_relay_txes = node->m_tx_relay->fRelayTxes; peer_filter_not_null = node->m_tx_relay->pfilter != nullptr; } NodeEvictionCandidate candidate = { node->GetId(), node->nTimeConnected, node->nMinPingUsecTime, node->nLastBlockTime, node->nLastProofTime, node->nLastTXTime, HasAllDesirableServiceFlags(node->nServices), peer_relay_txes, peer_filter_not_null, node->nKeyedNetGroup, node->m_prefer_evict, node->addr.IsLocal(), node->m_avalanche_state ? node->m_avalanche_state->getAvailabilityScore() : -std::numeric_limits::infinity()}; vEvictionCandidates.push_back(candidate); } } const std::optional node_id_to_evict = SelectNodeToEvict(std::move(vEvictionCandidates)); if (!node_id_to_evict) { return false; } LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (pnode->GetId() == *node_id_to_evict) { pnode->fDisconnect = true; return true; } } return false; } void CConnman::AcceptConnection(const ListenSocket &hListenSocket) { struct sockaddr_storage sockaddr; socklen_t len = sizeof(sockaddr); SOCKET hSocket = accept(hListenSocket.socket, (struct sockaddr *)&sockaddr, &len); CAddress addr; int nInbound = 0; int nMaxInbound = nMaxConnections - m_max_outbound; if (hSocket != INVALID_SOCKET) { if (!addr.SetSockAddr((const struct sockaddr *)&sockaddr)) { LogPrintf("Warning: Unknown socket family\n"); } } NetPermissionFlags permissionFlags = NetPermissionFlags::PF_NONE; hListenSocket.AddSocketPermissionFlags(permissionFlags); AddWhitelistPermissionFlags(permissionFlags, addr); bool legacyWhitelisted = false; if (NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::PF_ISIMPLICIT)) { NetPermissions::ClearFlag(permissionFlags, PF_ISIMPLICIT); if (gArgs.GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY)) { NetPermissions::AddFlag(permissionFlags, PF_FORCERELAY); } if (gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) { NetPermissions::AddFlag(permissionFlags, PF_RELAY); } NetPermissions::AddFlag(permissionFlags, PF_MEMPOOL); NetPermissions::AddFlag(permissionFlags, PF_NOBAN); legacyWhitelisted = true; } { LOCK(cs_vNodes); for (const CNode *pnode : vNodes) { if (pnode->IsInboundConn()) { nInbound++; } } } if (hSocket == INVALID_SOCKET) { int nErr = WSAGetLastError(); if (nErr != WSAEWOULDBLOCK) { LogPrintf("socket error accept failed: %s\n", NetworkErrorString(nErr)); } return; } if (!fNetworkActive) { LogPrintf("connection from %s dropped: not accepting new connections\n", addr.ToString()); CloseSocket(hSocket); return; } if (!IsSelectableSocket(hSocket)) { LogPrintf("connection from %s dropped: non-selectable socket\n", addr.ToString()); CloseSocket(hSocket); return; } // According to the internet TCP_NODELAY is not carried into accepted // sockets on all platforms. Set it again here just to be sure. SetSocketNoDelay(hSocket); // Don't accept connections from banned peers. bool banned = m_banman && m_banman->IsBanned(addr); if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::PF_NOBAN) && banned) { LogPrint(BCLog::NET, "connection from %s dropped (banned)\n", addr.ToString()); CloseSocket(hSocket); return; } // Only accept connections from discouraged peers if our inbound slots // aren't (almost) full. bool discouraged = m_banman && m_banman->IsDiscouraged(addr); if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::PF_NOBAN) && nInbound + 1 >= nMaxInbound && discouraged) { LogPrint(BCLog::NET, "connection from %s dropped (discouraged)\n", addr.ToString()); CloseSocket(hSocket); return; } if (nInbound >= nMaxInbound) { if (!AttemptToEvictConnection()) { // No connection to evict, disconnect the new connection LogPrint(BCLog::NET, "failed to find an eviction candidate - " "connection dropped (full)\n"); CloseSocket(hSocket); return; } } NodeId id = GetNewNodeId(); uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE) .Write(id) .Finalize(); uint64_t extra_entropy = GetDeterministicRandomizer(RANDOMIZER_ID_EXTRAENTROPY) .Write(id) .Finalize(); CAddress addr_bind = GetBindAddress(hSocket); ServiceFlags nodeServices = nLocalServices; if (NetPermissions::HasFlag(permissionFlags, PF_BLOOMFILTER)) { nodeServices = static_cast(nodeServices | NODE_BLOOM); } CNode *pnode = new CNode(id, nodeServices, GetBestHeight(), hSocket, addr, CalculateKeyedNetGroup(addr), nonce, extra_entropy, addr_bind, "", ConnectionType::INBOUND); pnode->AddRef(); pnode->m_permissionFlags = permissionFlags; // If this flag is present, the user probably expect that RPC and QT report // it as whitelisted (backward compatibility) pnode->m_legacyWhitelisted = legacyWhitelisted; pnode->m_prefer_evict = discouraged; m_msgproc->InitializeNode(*config, pnode); LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToString()); { LOCK(cs_vNodes); vNodes.push_back(pnode); } // We received a new connection, harvest entropy from the time (and our peer // count) RandAddEvent(uint32_t(id)); } void CConnman::DisconnectNodes() { { LOCK(cs_vNodes); if (!fNetworkActive) { // Disconnect any connected nodes for (CNode *pnode : vNodes) { if (!pnode->fDisconnect) { LogPrint(BCLog::NET, "Network not active, dropping peer=%d\n", pnode->GetId()); pnode->fDisconnect = true; } } } // Disconnect unused nodes std::vector vNodesCopy = vNodes; for (CNode *pnode : vNodesCopy) { if (pnode->fDisconnect) { // remove from vNodes vNodes.erase(remove(vNodes.begin(), vNodes.end(), pnode), vNodes.end()); // release outbound grant (if any) pnode->grantOutbound.Release(); // close socket and cleanup pnode->CloseSocketDisconnect(); // hold in disconnected pool until all refs are released pnode->Release(); vNodesDisconnected.push_back(pnode); } } } { // Delete disconnected nodes std::list vNodesDisconnectedCopy = vNodesDisconnected; for (CNode *pnode : vNodesDisconnectedCopy) { // wait until threads are done using it if (pnode->GetRefCount() <= 0) { bool fDelete = false; { TRY_LOCK(pnode->cs_vSend, lockSend); if (lockSend) { fDelete = true; } } if (fDelete) { vNodesDisconnected.remove(pnode); DeleteNode(pnode); } } } } } void CConnman::NotifyNumConnectionsChanged() { size_t vNodesSize; { LOCK(cs_vNodes); vNodesSize = vNodes.size(); } if (vNodesSize != nPrevNodeCount) { nPrevNodeCount = vNodesSize; if (clientInterface) { clientInterface->NotifyNumConnectionsChanged(vNodesSize); } } } void CConnman::InactivityCheck(CNode *pnode) { int64_t nTime = GetSystemTimeInSeconds(); if (nTime - pnode->nTimeConnected > m_peer_connect_timeout) { if (pnode->nLastRecv == 0 || pnode->nLastSend == 0) { LogPrint(BCLog::NET, "socket no message in first %i seconds, %d %d from %d\n", m_peer_connect_timeout, pnode->nLastRecv != 0, pnode->nLastSend != 0, pnode->GetId()); pnode->fDisconnect = true; } else if (nTime - pnode->nLastSend > TIMEOUT_INTERVAL) { LogPrintf("socket sending timeout: %is\n", nTime - pnode->nLastSend); pnode->fDisconnect = true; } else if (nTime - pnode->nLastRecv > (pnode->GetCommonVersion() > BIP0031_VERSION ? TIMEOUT_INTERVAL : 90 * 60)) { LogPrintf("socket receive timeout: %is\n", nTime - pnode->nLastRecv); pnode->fDisconnect = true; } else if (pnode->nPingNonceSent && pnode->m_ping_start.load() + std::chrono::seconds{TIMEOUT_INTERVAL} < GetTime()) { LogPrintf("ping timeout: %fs\n", 0.000001 * count_microseconds( GetTime() - pnode->m_ping_start.load())); pnode->fDisconnect = true; } else if (!pnode->fSuccessfullyConnected) { LogPrint(BCLog::NET, "version handshake timeout from %d\n", pnode->GetId()); pnode->fDisconnect = true; } } } bool CConnman::GenerateSelectSet(std::set &recv_set, std::set &send_set, std::set &error_set) { for (const ListenSocket &hListenSocket : vhListenSocket) { recv_set.insert(hListenSocket.socket); } { LOCK(cs_vNodes); for (CNode *pnode : vNodes) { // Implement the following logic: // * If there is data to send, select() for sending data. As this // only happens when optimistic write failed, we choose to first // drain the write buffer in this case before receiving more. This // avoids needlessly queueing received data, if the remote peer is // not themselves receiving data. This means properly utilizing // TCP flow control signalling. // * Otherwise, if there is space left in the receive buffer, // select() for receiving data. // * Hand off all complete messages to the processor, to be handled // without blocking here. bool select_recv = !pnode->fPauseRecv; bool select_send; { LOCK(pnode->cs_vSend); select_send = !pnode->vSendMsg.empty(); } LOCK(pnode->cs_hSocket); if (pnode->hSocket == INVALID_SOCKET) { continue; } error_set.insert(pnode->hSocket); if (select_send) { send_set.insert(pnode->hSocket); continue; } if (select_recv) { recv_set.insert(pnode->hSocket); } } } return !recv_set.empty() || !send_set.empty() || !error_set.empty(); } #ifdef USE_POLL void CConnman::SocketEvents(std::set &recv_set, std::set &send_set, std::set &error_set) { std::set recv_select_set, send_select_set, error_select_set; if (!GenerateSelectSet(recv_select_set, send_select_set, error_select_set)) { interruptNet.sleep_for( std::chrono::milliseconds(SELECT_TIMEOUT_MILLISECONDS)); return; } std::unordered_map pollfds; for (SOCKET socket_id : recv_select_set) { pollfds[socket_id].fd = socket_id; pollfds[socket_id].events |= POLLIN; } for (SOCKET socket_id : send_select_set) { pollfds[socket_id].fd = socket_id; pollfds[socket_id].events |= POLLOUT; } for (SOCKET socket_id : error_select_set) { pollfds[socket_id].fd = socket_id; // These flags are ignored, but we set them for clarity pollfds[socket_id].events |= POLLERR | POLLHUP; } std::vector vpollfds; vpollfds.reserve(pollfds.size()); for (auto it : pollfds) { vpollfds.push_back(std::move(it.second)); } if (poll(vpollfds.data(), vpollfds.size(), SELECT_TIMEOUT_MILLISECONDS) < 0) { return; } if (interruptNet) { return; } for (struct pollfd pollfd_entry : vpollfds) { if (pollfd_entry.revents & POLLIN) { recv_set.insert(pollfd_entry.fd); } if (pollfd_entry.revents & POLLOUT) { send_set.insert(pollfd_entry.fd); } if (pollfd_entry.revents & (POLLERR | POLLHUP)) { error_set.insert(pollfd_entry.fd); } } } #else void CConnman::SocketEvents(std::set &recv_set, std::set &send_set, std::set &error_set) { std::set recv_select_set, send_select_set, error_select_set; if (!GenerateSelectSet(recv_select_set, send_select_set, error_select_set)) { interruptNet.sleep_for( std::chrono::milliseconds(SELECT_TIMEOUT_MILLISECONDS)); return; } // // Find which sockets have data to receive // struct timeval timeout; timeout.tv_sec = 0; // frequency to poll pnode->vSend timeout.tv_usec = SELECT_TIMEOUT_MILLISECONDS * 1000; fd_set fdsetRecv; fd_set fdsetSend; fd_set fdsetError; FD_ZERO(&fdsetRecv); FD_ZERO(&fdsetSend); FD_ZERO(&fdsetError); SOCKET hSocketMax = 0; for (SOCKET hSocket : recv_select_set) { FD_SET(hSocket, &fdsetRecv); hSocketMax = std::max(hSocketMax, hSocket); } for (SOCKET hSocket : send_select_set) { FD_SET(hSocket, &fdsetSend); hSocketMax = std::max(hSocketMax, hSocket); } for (SOCKET hSocket : error_select_set) { FD_SET(hSocket, &fdsetError); hSocketMax = std::max(hSocketMax, hSocket); } int nSelect = select(hSocketMax + 1, &fdsetRecv, &fdsetSend, &fdsetError, &timeout); if (interruptNet) { return; } if (nSelect == SOCKET_ERROR) { int nErr = WSAGetLastError(); LogPrintf("socket select error %s\n", NetworkErrorString(nErr)); for (unsigned int i = 0; i <= hSocketMax; i++) { FD_SET(i, &fdsetRecv); } FD_ZERO(&fdsetSend); FD_ZERO(&fdsetError); if (!interruptNet.sleep_for( std::chrono::milliseconds(SELECT_TIMEOUT_MILLISECONDS))) { return; } } for (SOCKET hSocket : recv_select_set) { if (FD_ISSET(hSocket, &fdsetRecv)) { recv_set.insert(hSocket); } } for (SOCKET hSocket : send_select_set) { if (FD_ISSET(hSocket, &fdsetSend)) { send_set.insert(hSocket); } } for (SOCKET hSocket : error_select_set) { if (FD_ISSET(hSocket, &fdsetError)) { error_set.insert(hSocket); } } } #endif void CConnman::SocketHandler() { std::set recv_set, send_set, error_set; SocketEvents(recv_set, send_set, error_set); if (interruptNet) { return; } // // Accept new connections // for (const ListenSocket &hListenSocket : vhListenSocket) { if (hListenSocket.socket != INVALID_SOCKET && recv_set.count(hListenSocket.socket) > 0) { AcceptConnection(hListenSocket); } } // // Service each socket // std::vector vNodesCopy; { LOCK(cs_vNodes); vNodesCopy = vNodes; for (CNode *pnode : vNodesCopy) { pnode->AddRef(); } } for (CNode *pnode : vNodesCopy) { if (interruptNet) { return; } // // Receive // bool recvSet = false; bool sendSet = false; bool errorSet = false; { LOCK(pnode->cs_hSocket); if (pnode->hSocket == INVALID_SOCKET) { continue; } recvSet = recv_set.count(pnode->hSocket) > 0; sendSet = send_set.count(pnode->hSocket) > 0; errorSet = error_set.count(pnode->hSocket) > 0; } if (recvSet || errorSet) { // typical socket buffer is 8K-64K char pchBuf[0x10000]; int32_t nBytes = 0; { LOCK(pnode->cs_hSocket); if (pnode->hSocket == INVALID_SOCKET) { continue; } nBytes = recv(pnode->hSocket, pchBuf, sizeof(pchBuf), MSG_DONTWAIT); } if (nBytes > 0) { bool notify = false; if (!pnode->ReceiveMsgBytes(*config, pchBuf, nBytes, notify)) { pnode->CloseSocketDisconnect(); } RecordBytesRecv(nBytes); if (notify) { size_t nSizeAdded = 0; auto it(pnode->vRecvMsg.begin()); for (; it != pnode->vRecvMsg.end(); ++it) { // vRecvMsg contains only completed CNetMessage // the single possible partially deserialized message // are held by TransportDeserializer nSizeAdded += it->m_raw_message_size; } { LOCK(pnode->cs_vProcessMsg); pnode->vProcessMsg.splice(pnode->vProcessMsg.end(), pnode->vRecvMsg, pnode->vRecvMsg.begin(), it); pnode->nProcessQueueSize += nSizeAdded; pnode->fPauseRecv = pnode->nProcessQueueSize > nReceiveFloodSize; } WakeMessageHandler(); } } else if (nBytes == 0) { // socket closed gracefully if (!pnode->fDisconnect) { LogPrint(BCLog::NET, "socket closed for peer=%d\n", pnode->GetId()); } pnode->CloseSocketDisconnect(); } else if (nBytes < 0) { // error int nErr = WSAGetLastError(); if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS) { if (!pnode->fDisconnect) { LogPrint(BCLog::NET, "socket recv error for peer=%d: %s\n", pnode->GetId(), NetworkErrorString(nErr)); } pnode->CloseSocketDisconnect(); } } } // // Send // if (sendSet) { LOCK(pnode->cs_vSend); size_t nBytes = SocketSendData(pnode); if (nBytes) { RecordBytesSent(nBytes); } } InactivityCheck(pnode); } { LOCK(cs_vNodes); for (CNode *pnode : vNodesCopy) { pnode->Release(); } } } void CConnman::ThreadSocketHandler() { while (!interruptNet) { DisconnectNodes(); NotifyNumConnectionsChanged(); SocketHandler(); } } void CConnman::WakeMessageHandler() { { LOCK(mutexMsgProc); fMsgProcWake = true; } condMsgProc.notify_one(); } #ifdef USE_UPNP static CThreadInterrupt g_upnp_interrupt; static std::thread g_upnp_thread; static void ThreadMapPort() { std::string port = strprintf("%u", GetListenPort()); const char *multicastif = nullptr; const char *minissdpdpath = nullptr; struct UPNPDev *devlist = nullptr; char lanaddr[64]; int error = 0; #if MINIUPNPC_API_VERSION < 14 devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0, 0, &error); #else devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0, 0, 2, &error); #endif struct UPNPUrls urls; struct IGDdatas data; int r; r = UPNP_GetValidIGD(devlist, &urls, &data, lanaddr, sizeof(lanaddr)); if (r == 1) { if (fDiscover) { char externalIPAddress[40]; r = UPNP_GetExternalIPAddress( urls.controlURL, data.first.servicetype, externalIPAddress); if (r != UPNPCOMMAND_SUCCESS) { LogPrintf("UPnP: GetExternalIPAddress() returned %d\n", r); } else { if (externalIPAddress[0]) { CNetAddr resolved; if (LookupHost(externalIPAddress, resolved, false)) { LogPrintf("UPnP: ExternalIPAddress = %s\n", resolved.ToString()); AddLocal(resolved, LOCAL_UPNP); } } else { LogPrintf("UPnP: GetExternalIPAddress failed.\n"); } } } std::string strDesc = PACKAGE_NAME " " + FormatFullVersion(); do { r = UPNP_AddPortMapping(urls.controlURL, data.first.servicetype, port.c_str(), port.c_str(), lanaddr, strDesc.c_str(), "TCP", 0, "0"); if (r != UPNPCOMMAND_SUCCESS) { LogPrintf( "AddPortMapping(%s, %s, %s) failed with code %d (%s)\n", port, port, lanaddr, r, strupnperror(r)); } else { LogPrintf("UPnP Port Mapping successful.\n"); } } while (g_upnp_interrupt.sleep_for(std::chrono::minutes(20))); r = UPNP_DeletePortMapping(urls.controlURL, data.first.servicetype, port.c_str(), "TCP", 0); LogPrintf("UPNP_DeletePortMapping() returned: %d\n", r); freeUPNPDevlist(devlist); devlist = nullptr; FreeUPNPUrls(&urls); } else { LogPrintf("No valid UPnP IGDs found\n"); freeUPNPDevlist(devlist); devlist = nullptr; if (r != 0) { FreeUPNPUrls(&urls); } } } void StartMapPort() { if (!g_upnp_thread.joinable()) { assert(!g_upnp_interrupt); g_upnp_thread = std::thread( (std::bind(&TraceThread, "upnp", &ThreadMapPort))); } } void InterruptMapPort() { if (g_upnp_thread.joinable()) { g_upnp_interrupt(); } } void StopMapPort() { if (g_upnp_thread.joinable()) { g_upnp_thread.join(); g_upnp_interrupt.reset(); } } #else void StartMapPort() { // Intentionally left blank. } void InterruptMapPort() { // Intentionally left blank. } void StopMapPort() { // Intentionally left blank. } #endif void CConnman::ThreadDNSAddressSeed() { FastRandomContext rng; std::vector seeds = GetRandomizedDNSSeeds(config->GetChainParams()); // Number of seeds left before testing if we have enough connections int seeds_right_now = 0; int found = 0; if (gArgs.GetBoolArg("-forcednsseed", DEFAULT_FORCEDNSSEED)) { // When -forcednsseed is provided, query all. seeds_right_now = seeds.size(); } else if (addrman.size() == 0) { // If we have no known peers, query all. // This will occur on the first run, or if peers.dat has been // deleted. seeds_right_now = seeds.size(); } // goal: only query DNS seed if address need is acute // * If we have a reasonable number of peers in addrman, spend // some time trying them first. This improves user privacy by // creating fewer identifying DNS requests, reduces trust by // giving seeds less influence on the network topology, and // reduces traffic to the seeds. // * When querying DNS seeds query a few at once, this ensures // that we don't give DNS seeds the ability to eclipse nodes // that query them. // * If we continue having problems, eventually query all the // DNS seeds, and if that fails too, also try the fixed seeds. // (done in ThreadOpenConnections) const std::chrono::seconds seeds_wait_time = (addrman.size() >= DNSSEEDS_DELAY_PEER_THRESHOLD ? DNSSEEDS_DELAY_MANY_PEERS : DNSSEEDS_DELAY_FEW_PEERS); for (const std::string &seed : seeds) { if (seeds_right_now == 0) { seeds_right_now += DNSSEEDS_TO_QUERY_AT_ONCE; if (addrman.size() > 0) { LogPrintf("Waiting %d seconds before querying DNS seeds.\n", seeds_wait_time.count()); std::chrono::seconds to_wait = seeds_wait_time; while (to_wait.count() > 0) { // if sleeping for the MANY_PEERS interval, wake up // early to see if we have enough peers and can stop // this thread entirely freeing up its resources std::chrono::seconds w = std::min(DNSSEEDS_DELAY_FEW_PEERS, to_wait); if (!interruptNet.sleep_for(w)) { return; } to_wait -= w; int nRelevant = 0; { LOCK(cs_vNodes); for (const CNode *pnode : vNodes) { if (pnode->fSuccessfullyConnected && pnode->IsOutboundOrBlockRelayConn()) { ++nRelevant; } } } if (nRelevant >= 2) { if (found > 0) { LogPrintf("%d addresses found from DNS seeds\n", found); LogPrintf( "P2P peers available. Finished DNS seeding.\n"); } else { LogPrintf( "P2P peers available. Skipped DNS seeding.\n"); } return; } } } } if (interruptNet) { return; } // hold off on querying seeds if P2P network deactivated if (!fNetworkActive) { LogPrintf("Waiting for network to be reactivated before querying " "DNS seeds.\n"); do { if (!interruptNet.sleep_for(std::chrono::seconds{1})) { return; } } while (!fNetworkActive); } LogPrintf("Loading addresses from DNS seed %s\n", seed); if (HaveNameProxy()) { AddAddrFetch(seed); } else { std::vector vIPs; std::vector vAdd; ServiceFlags requiredServiceBits = GetDesirableServiceFlags(NODE_NONE); std::string host = strprintf("x%x.%s", requiredServiceBits, seed); CNetAddr resolveSource; if (!resolveSource.SetInternal(host)) { continue; } // Limits number of IPs learned from a DNS seed unsigned int nMaxIPs = 256; if (LookupHost(host, vIPs, nMaxIPs, true)) { for (const CNetAddr &ip : vIPs) { int nOneDay = 24 * 3600; CAddress addr = CAddress( CService(ip, config->GetChainParams().GetDefaultPort()), requiredServiceBits); // Use a random age between 3 and 7 days old. addr.nTime = GetTime() - 3 * nOneDay - rng.randrange(4 * nOneDay); vAdd.push_back(addr); found++; } addrman.Add(vAdd, resolveSource); } else { // We now avoid directly using results from DNS Seeds which do // not support service bit filtering, instead using them as a // addrfetch to get nodes with our desired service bits. AddAddrFetch(seed); } } --seeds_right_now; } LogPrintf("%d addresses found from DNS seeds\n", found); } void CConnman::DumpAddresses() { int64_t nStart = GetTimeMillis(); CAddrDB adb(config->GetChainParams()); adb.Write(addrman); LogPrint(BCLog::NET, "Flushed %d addresses to peers.dat %dms\n", addrman.size(), GetTimeMillis() - nStart); } void CConnman::ProcessAddrFetch() { std::string strDest; { LOCK(m_addr_fetches_mutex); if (m_addr_fetches.empty()) { return; } strDest = m_addr_fetches.front(); m_addr_fetches.pop_front(); } CAddress addr; CSemaphoreGrant grant(*semOutbound, true); if (grant) { OpenNetworkConnection(addr, false, &grant, strDest.c_str(), ConnectionType::ADDR_FETCH); } } bool CConnman::GetTryNewOutboundPeer() { return m_try_another_outbound_peer; } void CConnman::SetTryNewOutboundPeer(bool flag) { m_try_another_outbound_peer = flag; LogPrint(BCLog::NET, "net: setting try another outbound peer=%s\n", flag ? "true" : "false"); } // Return the number of peers we have over our outbound connection limit. // Exclude peers that are marked for disconnect, or are going to be disconnected // soon (eg one-shots and feelers). // Also exclude peers that haven't finished initial connection handshake yet (so // that we don't decide we're over our desired connection limit, and then evict // some peer that has finished the handshake). int CConnman::GetExtraOutboundCount() { int nOutbound = 0; { LOCK(cs_vNodes); for (const CNode *pnode : vNodes) { if (pnode->fSuccessfullyConnected && !pnode->fDisconnect && pnode->IsOutboundOrBlockRelayConn()) { ++nOutbound; } } } return std::max( nOutbound - m_max_outbound_full_relay - m_max_outbound_block_relay, 0); } void CConnman::ThreadOpenConnections(const std::vector connect) { // Connect to specific addresses if (!connect.empty()) { for (int64_t nLoop = 0;; nLoop++) { ProcessAddrFetch(); for (const std::string &strAddr : connect) { CAddress addr(CService(), NODE_NONE); OpenNetworkConnection(addr, false, nullptr, strAddr.c_str(), ConnectionType::MANUAL); for (int i = 0; i < 10 && i < nLoop; i++) { if (!interruptNet.sleep_for( std::chrono::milliseconds(500))) { return; } } } if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) { return; } } } // Initiate network connections int64_t nStart = GetTime(); // Minimum time before next feeler connection (in microseconds). int64_t nNextFeeler = PoissonNextSend(nStart * 1000 * 1000, FEELER_INTERVAL); while (!interruptNet) { ProcessAddrFetch(); if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) { return; } CSemaphoreGrant grant(*semOutbound); if (interruptNet) { return; } // Add seed nodes if DNS seeds are all down (an infrastructure attack?). // Note that we only do this if we started with an empty peers.dat, // (in which case we will query DNS seeds immediately) *and* the DNS // seeds have not returned any results. if (addrman.size() == 0 && (GetTime() - nStart > 60)) { static bool done = false; if (!done) { LogPrintf("Adding fixed seed nodes as DNS doesn't seem to be " "available.\n"); CNetAddr local; local.SetInternal("fixedseeds"); addrman.Add(convertSeed6(config->GetChainParams().FixedSeeds()), local); done = true; } } // // Choose an address to connect to based on most recently seen // CAddress addrConnect; // Only connect out to one peer per network group (/16 for IPv4). int nOutboundFullRelay = 0; int nOutboundBlockRelay = 0; std::set> setConnected; { LOCK(cs_vNodes); for (const CNode *pnode : vNodes) { if (pnode->IsFullOutboundConn()) { nOutboundFullRelay++; } if (pnode->IsBlockOnlyConn()) { nOutboundBlockRelay++; } // Netgroups for inbound and manual peers are not excluded // because our goal here is to not use multiple of our // limited outbound slots on a single netgroup but inbound // and manual peers do not use our outbound slots. Inbound // peers also have the added issue that they could be attacker // controlled and could be used to prevent us from connecting // to particular hosts if we used them here. switch (pnode->m_conn_type) { case ConnectionType::INBOUND: case ConnectionType::MANUAL: break; case ConnectionType::OUTBOUND_FULL_RELAY: case ConnectionType::BLOCK_RELAY: case ConnectionType::ADDR_FETCH: case ConnectionType::FEELER: setConnected.insert( pnode->addr.GetGroup(addrman.m_asmap)); } // no default case, so the compiler can warn about missing // cases } } ConnectionType conn_type = ConnectionType::OUTBOUND_FULL_RELAY; int64_t nTime = GetTimeMicros(); bool fFeeler = false; // Determine what type of connection to open. Opening // OUTBOUND_FULL_RELAY connections gets the highest priority until we // meet our full-relay capacity. Then we open BLOCK_RELAY connection // until we hit our block-relay-only peer limit. // GetTryNewOutboundPeer() gets set when a stale tip is detected, so we // try opening an additional OUTBOUND_FULL_RELAY connection. If none of // these conditions are met, check the nNextFeeler timer to decide if // we should open a FEELER. if (nOutboundFullRelay < m_max_outbound_full_relay) { // OUTBOUND_FULL_RELAY } else if (nOutboundBlockRelay < m_max_outbound_block_relay) { conn_type = ConnectionType::BLOCK_RELAY; } else if (GetTryNewOutboundPeer()) { // OUTBOUND_FULL_RELAY } else if (nTime > nNextFeeler) { nNextFeeler = PoissonNextSend(nTime, FEELER_INTERVAL); conn_type = ConnectionType::FEELER; fFeeler = true; } else { // skip to next iteration of while loop continue; } addrman.ResolveCollisions(); int64_t nANow = GetAdjustedTime(); int nTries = 0; while (!interruptNet) { CAddrInfo addr = addrman.SelectTriedCollision(); // SelectTriedCollision returns an invalid address if it is empty. if (!fFeeler || !addr.IsValid()) { addr = addrman.Select(fFeeler); } // Require outbound connections, other than feelers, to be to // distinct network groups if (!fFeeler && setConnected.count(addr.GetGroup(addrman.m_asmap))) { break; } // if we selected an invalid or local address, restart if (!addr.IsValid() || IsLocal(addr)) { break; } // If we didn't find an appropriate destination after trying 100 // addresses fetched from addrman, stop this loop, and let the outer // loop run again (which sleeps, adds seed nodes, recalculates // already-connected network ranges, ...) before trying new addrman // addresses. nTries++; if (nTries > 100) { break; } if (!IsReachable(addr)) { continue; } // only consider very recently tried nodes after 30 failed attempts if (nANow - addr.nLastTry < 600 && nTries < 30) { continue; } // for non-feelers, require all the services we'll want, // for feelers, only require they be a full node (only because most // SPV clients don't have a good address DB available) if (!fFeeler && !HasAllDesirableServiceFlags(addr.nServices)) { continue; } if (fFeeler && !MayHaveUsefulAddressDB(addr.nServices)) { continue; } // do not allow non-default ports, unless after 50 invalid addresses // selected already. if (addr.GetPort() != config->GetChainParams().GetDefaultPort() && nTries < 50) { continue; } addrConnect = addr; break; } if (addrConnect.IsValid()) { if (fFeeler) { // Add small amount of random noise before connection to avoid // synchronization. int randsleep = GetRandInt(FEELER_SLEEP_WINDOW * 1000); if (!interruptNet.sleep_for( std::chrono::milliseconds(randsleep))) { return; } LogPrint(BCLog::NET, "Making feeler connection to %s\n", addrConnect.ToString()); } OpenNetworkConnection(addrConnect, int(setConnected.size()) >= std::min(nMaxConnections - 1, 2), &grant, nullptr, conn_type); } } } std::vector CConnman::GetAddedNodeInfo() { std::vector ret; std::list lAddresses(0); { LOCK(cs_vAddedNodes); ret.reserve(vAddedNodes.size()); std::copy(vAddedNodes.cbegin(), vAddedNodes.cend(), std::back_inserter(lAddresses)); } // Build a map of all already connected addresses (by IP:port and by name) // to inbound/outbound and resolved CService std::map mapConnected; std::map> mapConnectedByName; { LOCK(cs_vNodes); for (const CNode *pnode : vNodes) { if (pnode->addr.IsValid()) { mapConnected[pnode->addr] = pnode->IsInboundConn(); } std::string addrName = pnode->GetAddrName(); if (!addrName.empty()) { mapConnectedByName[std::move(addrName)] = std::make_pair(pnode->IsInboundConn(), static_cast(pnode->addr)); } } } for (const std::string &strAddNode : lAddresses) { CService service(LookupNumeric(strAddNode, Params().GetDefaultPort())); AddedNodeInfo addedNode{strAddNode, CService(), false, false}; if (service.IsValid()) { // strAddNode is an IP:port auto it = mapConnected.find(service); if (it != mapConnected.end()) { addedNode.resolvedAddress = service; addedNode.fConnected = true; addedNode.fInbound = it->second; } } else { // strAddNode is a name auto it = mapConnectedByName.find(strAddNode); if (it != mapConnectedByName.end()) { addedNode.resolvedAddress = it->second.second; addedNode.fConnected = true; addedNode.fInbound = it->second.first; } } ret.emplace_back(std::move(addedNode)); } return ret; } void CConnman::ThreadOpenAddedConnections() { while (true) { CSemaphoreGrant grant(*semAddnode); std::vector vInfo = GetAddedNodeInfo(); bool tried = false; for (const AddedNodeInfo &info : vInfo) { if (!info.fConnected) { if (!grant.TryAcquire()) { // If we've used up our semaphore and need a new one, let's // not wait here since while we are waiting the // addednodeinfo state might change. break; } tried = true; CAddress addr(CService(), NODE_NONE); OpenNetworkConnection(addr, false, &grant, info.strAddedNode.c_str(), ConnectionType::MANUAL); if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) { return; } } } // Retry every 60 seconds if a connection was attempted, otherwise two // seconds. if (!interruptNet.sleep_for(std::chrono::seconds(tried ? 60 : 2))) { return; } } } // If successful, this moves the passed grant to the constructed node. void CConnman::OpenNetworkConnection(const CAddress &addrConnect, bool fCountFailure, CSemaphoreGrant *grantOutbound, const char *pszDest, ConnectionType conn_type) { assert(conn_type != ConnectionType::INBOUND); // // Initiate outbound network connection // if (interruptNet) { return; } if (!fNetworkActive) { return; } if (!pszDest) { bool banned_or_discouraged = m_banman && (m_banman->IsDiscouraged(addrConnect) || m_banman->IsBanned(addrConnect)); if (IsLocal(addrConnect) || FindNode(static_cast(addrConnect)) || banned_or_discouraged || FindNode(addrConnect.ToStringIPPort())) { return; } } else if (FindNode(std::string(pszDest))) { return; } CNode *pnode = ConnectNode(addrConnect, pszDest, fCountFailure, conn_type); if (!pnode) { return; } if (grantOutbound) { grantOutbound->MoveTo(pnode->grantOutbound); } m_msgproc->InitializeNode(*config, pnode); { LOCK(cs_vNodes); vNodes.push_back(pnode); } } void CConnman::ThreadMessageHandler() { while (!flagInterruptMsgProc) { std::vector vNodesCopy; { LOCK(cs_vNodes); vNodesCopy = vNodes; for (CNode *pnode : vNodesCopy) { pnode->AddRef(); } } bool fMoreWork = false; for (CNode *pnode : vNodesCopy) { if (pnode->fDisconnect) { continue; } // Receive messages bool fMoreNodeWork = m_msgproc->ProcessMessages( *config, pnode, flagInterruptMsgProc); fMoreWork |= (fMoreNodeWork && !pnode->fPauseSend); if (flagInterruptMsgProc) { return; } // Send messages { LOCK(pnode->cs_sendProcessing); m_msgproc->SendMessages(*config, pnode, flagInterruptMsgProc); } if (flagInterruptMsgProc) { return; } } { LOCK(cs_vNodes); for (CNode *pnode : vNodesCopy) { pnode->Release(); } } WAIT_LOCK(mutexMsgProc, lock); if (!fMoreWork) { condMsgProc.wait_until(lock, std::chrono::steady_clock::now() + std::chrono::milliseconds(100), [this]() EXCLUSIVE_LOCKS_REQUIRED( mutexMsgProc) { return fMsgProcWake; }); } fMsgProcWake = false; } } bool CConnman::BindListenPort(const CService &addrBind, bilingual_str &strError, NetPermissionFlags permissions) { int nOne = 1; // Create socket for listening for incoming connections struct sockaddr_storage sockaddr; socklen_t len = sizeof(sockaddr); if (!addrBind.GetSockAddr((struct sockaddr *)&sockaddr, &len)) { strError = strprintf( Untranslated("Error: Bind address family for %s not supported"), addrBind.ToString()); LogPrintf("%s\n", strError.original); return false; } SOCKET hListenSocket = CreateSocket(addrBind); if (hListenSocket == INVALID_SOCKET) { strError = strprintf(Untranslated("Error: Couldn't open socket for incoming " "connections (socket returned error %s)"), NetworkErrorString(WSAGetLastError())); LogPrintf("%s\n", strError.original); return false; } // Allow binding if the port is still in TIME_WAIT state after // the program was closed and restarted. setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (sockopt_arg_type)&nOne, sizeof(int)); // Some systems don't have IPV6_V6ONLY but are always v6only; others do have // the option and enable it by default or not. Try to enable it, if // possible. if (addrBind.IsIPv6()) { #ifdef IPV6_V6ONLY setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_V6ONLY, (sockopt_arg_type)&nOne, sizeof(int)); #endif #ifdef WIN32 int nProtLevel = PROTECTION_LEVEL_UNRESTRICTED; setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_PROTECTION_LEVEL, (sockopt_arg_type)&nProtLevel, sizeof(int)); #endif } if (::bind(hListenSocket, (struct sockaddr *)&sockaddr, len) == SOCKET_ERROR) { int nErr = WSAGetLastError(); if (nErr == WSAEADDRINUSE) { strError = strprintf(_("Unable to bind to %s on this computer. %s " "is probably already running."), addrBind.ToString(), PACKAGE_NAME); } else { strError = strprintf(_("Unable to bind to %s on this computer " "(bind returned error %s)"), addrBind.ToString(), NetworkErrorString(nErr)); } LogPrintf("%s\n", strError.original); CloseSocket(hListenSocket); return false; } LogPrintf("Bound to %s\n", addrBind.ToString()); // Listen for incoming connections if (listen(hListenSocket, SOMAXCONN) == SOCKET_ERROR) { strError = strprintf(_("Error: Listening for incoming connections " "failed (listen returned error %s)"), NetworkErrorString(WSAGetLastError())); LogPrintf("%s\n", strError.original); CloseSocket(hListenSocket); return false; } vhListenSocket.push_back(ListenSocket(hListenSocket, permissions)); if (addrBind.IsRoutable() && fDiscover && (permissions & PF_NOBAN) == 0) { AddLocal(addrBind, LOCAL_BIND); } return true; } void Discover() { if (!fDiscover) { return; } #ifdef WIN32 // Get local host IP char pszHostName[256] = ""; if (gethostname(pszHostName, sizeof(pszHostName)) != SOCKET_ERROR) { std::vector vaddr; if (LookupHost(pszHostName, vaddr, 0, true)) { for (const CNetAddr &addr : vaddr) { if (AddLocal(addr, LOCAL_IF)) { LogPrintf("%s: %s - %s\n", __func__, pszHostName, addr.ToString()); } } } } #elif (HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS) // Get local host ip struct ifaddrs *myaddrs; if (getifaddrs(&myaddrs) == 0) { for (struct ifaddrs *ifa = myaddrs; ifa != nullptr; ifa = ifa->ifa_next) { if (ifa->ifa_addr == nullptr || (ifa->ifa_flags & IFF_UP) == 0 || strcmp(ifa->ifa_name, "lo") == 0 || strcmp(ifa->ifa_name, "lo0") == 0) { continue; } if (ifa->ifa_addr->sa_family == AF_INET) { struct sockaddr_in *s4 = reinterpret_cast(ifa->ifa_addr); CNetAddr addr(s4->sin_addr); if (AddLocal(addr, LOCAL_IF)) { LogPrintf("%s: IPv4 %s: %s\n", __func__, ifa->ifa_name, addr.ToString()); } } else if (ifa->ifa_addr->sa_family == AF_INET6) { struct sockaddr_in6 *s6 = reinterpret_cast(ifa->ifa_addr); CNetAddr addr(s6->sin6_addr); if (AddLocal(addr, LOCAL_IF)) { LogPrintf("%s: IPv6 %s: %s\n", __func__, ifa->ifa_name, addr.ToString()); } } } freeifaddrs(myaddrs); } #endif } void CConnman::SetNetworkActive(bool active) { LogPrintf("%s: %s\n", __func__, active); if (fNetworkActive == active) { return; } fNetworkActive = active; uiInterface.NotifyNetworkActiveChanged(fNetworkActive); } CConnman::CConnman(const Config &configIn, uint64_t nSeed0In, uint64_t nSeed1In, bool network_active) : config(&configIn), nSeed0(nSeed0In), nSeed1(nSeed1In) { SetTryNewOutboundPeer(false); Options connOptions; Init(connOptions); SetNetworkActive(network_active); } NodeId CConnman::GetNewNodeId() { return nLastNodeId.fetch_add(1); } bool CConnman::Bind(const CService &addr, unsigned int flags, NetPermissionFlags permissions) { if (!(flags & BF_EXPLICIT) && !IsReachable(addr)) { return false; } bilingual_str strError; if (!BindListenPort(addr, strError, permissions)) { if ((flags & BF_REPORT_ERROR) && clientInterface) { clientInterface->ThreadSafeMessageBox( strError, "", CClientUIInterface::MSG_ERROR); } return false; } return true; } bool CConnman::InitBinds( const std::vector &binds, const std::vector &whiteBinds) { bool fBound = false; for (const auto &addrBind : binds) { fBound |= Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR), NetPermissionFlags::PF_NONE); } for (const auto &addrBind : whiteBinds) { fBound |= Bind(addrBind.m_service, (BF_EXPLICIT | BF_REPORT_ERROR), addrBind.m_flags); } if (binds.empty() && whiteBinds.empty()) { struct in_addr inaddr_any; inaddr_any.s_addr = INADDR_ANY; struct in6_addr inaddr6_any = IN6ADDR_ANY_INIT; fBound |= Bind(CService(inaddr6_any, GetListenPort()), BF_NONE, NetPermissionFlags::PF_NONE); fBound |= Bind(CService(inaddr_any, GetListenPort()), !fBound ? BF_REPORT_ERROR : BF_NONE, NetPermissionFlags::PF_NONE); } return fBound; } bool CConnman::Start(CScheduler &scheduler, const Options &connOptions) { Init(connOptions); { LOCK(cs_totalBytesRecv); nTotalBytesRecv = 0; } { LOCK(cs_totalBytesSent); nTotalBytesSent = 0; nMaxOutboundTotalBytesSentInCycle = 0; nMaxOutboundCycleStartTime = 0; } if (fListen && !InitBinds(connOptions.vBinds, connOptions.vWhiteBinds)) { if (clientInterface) { clientInterface->ThreadSafeMessageBox( _("Failed to listen on any port. Use -listen=0 if you want " "this."), "", CClientUIInterface::MSG_ERROR); } return false; } for (const auto &strDest : connOptions.vSeedNodes) { AddAddrFetch(strDest); } if (clientInterface) { clientInterface->InitMessage(_("Loading P2P addresses...").translated); } // Load addresses from peers.dat int64_t nStart = GetTimeMillis(); { CAddrDB adb(config->GetChainParams()); if (adb.Read(addrman)) { LogPrintf("Loaded %i addresses from peers.dat %dms\n", addrman.size(), GetTimeMillis() - nStart); } else { // Addrman can be in an inconsistent state after failure, reset it addrman.Clear(); LogPrintf("Invalid or missing peers.dat; recreating\n"); DumpAddresses(); } } uiInterface.InitMessage(_("Starting network threads...").translated); fAddressesInitialized = true; if (semOutbound == nullptr) { // initialize semaphore semOutbound = std::make_unique( std::min(m_max_outbound, nMaxConnections)); } if (semAddnode == nullptr) { // initialize semaphore semAddnode = std::make_unique(nMaxAddnode); } // // Start threads // assert(m_msgproc); InterruptSocks5(false); interruptNet.reset(); flagInterruptMsgProc = false; { LOCK(mutexMsgProc); fMsgProcWake = false; } // Send and receive from sockets, accept connections threadSocketHandler = std::thread( &TraceThread>, "net", std::function(std::bind(&CConnman::ThreadSocketHandler, this))); if (!gArgs.GetBoolArg("-dnsseed", true)) { LogPrintf("DNS seeding disabled\n"); } else { threadDNSAddressSeed = std::thread(&TraceThread>, "dnsseed", std::function( std::bind(&CConnman::ThreadDNSAddressSeed, this))); } // Initiate manual connections threadOpenAddedConnections = std::thread(&TraceThread>, "addcon", std::function(std::bind( &CConnman::ThreadOpenAddedConnections, this))); if (connOptions.m_use_addrman_outgoing && !connOptions.m_specified_outgoing.empty()) { if (clientInterface) { clientInterface->ThreadSafeMessageBox( _("Cannot provide specific connections and have addrman find " "outgoing connections at the same."), "", CClientUIInterface::MSG_ERROR); } return false; } if (connOptions.m_use_addrman_outgoing || !connOptions.m_specified_outgoing.empty()) { threadOpenConnections = std::thread(&TraceThread>, "opencon", std::function( std::bind(&CConnman::ThreadOpenConnections, this, connOptions.m_specified_outgoing))); } // Process messages threadMessageHandler = std::thread(&TraceThread>, "msghand", std::function( std::bind(&CConnman::ThreadMessageHandler, this))); // Dump network addresses scheduler.scheduleEvery( [this]() { this->DumpAddresses(); return true; }, DUMP_PEERS_INTERVAL); return true; } class CNetCleanup { public: CNetCleanup() {} ~CNetCleanup() { #ifdef WIN32 // Shutdown Windows Sockets WSACleanup(); #endif } }; static CNetCleanup instance_of_cnetcleanup; void CConnman::Interrupt() { { LOCK(mutexMsgProc); flagInterruptMsgProc = true; } condMsgProc.notify_all(); interruptNet(); InterruptSocks5(true); if (semOutbound) { for (int i = 0; i < m_max_outbound; i++) { semOutbound->post(); } } if (semAddnode) { for (int i = 0; i < nMaxAddnode; i++) { semAddnode->post(); } } } void CConnman::StopThreads() { if (threadMessageHandler.joinable()) { threadMessageHandler.join(); } if (threadOpenConnections.joinable()) { threadOpenConnections.join(); } if (threadOpenAddedConnections.joinable()) { threadOpenAddedConnections.join(); } if (threadDNSAddressSeed.joinable()) { threadDNSAddressSeed.join(); } if (threadSocketHandler.joinable()) { threadSocketHandler.join(); } } void CConnman::StopNodes() { if (fAddressesInitialized) { DumpAddresses(); fAddressesInitialized = false; } // Close sockets LOCK(cs_vNodes); for (CNode *pnode : vNodes) { pnode->CloseSocketDisconnect(); } for (ListenSocket &hListenSocket : vhListenSocket) { if (hListenSocket.socket != INVALID_SOCKET) { if (!CloseSocket(hListenSocket.socket)) { LogPrintf("CloseSocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError())); } } } // clean up some globals (to help leak detection) for (CNode *pnode : vNodes) { DeleteNode(pnode); } for (CNode *pnode : vNodesDisconnected) { DeleteNode(pnode); } vNodes.clear(); vNodesDisconnected.clear(); vhListenSocket.clear(); semOutbound.reset(); semAddnode.reset(); } void CConnman::DeleteNode(CNode *pnode) { assert(pnode); bool fUpdateConnectionTime = false; m_msgproc->FinalizeNode(*config, pnode->GetId(), fUpdateConnectionTime); if (fUpdateConnectionTime) { addrman.Connected(pnode->addr); } delete pnode; } CConnman::~CConnman() { Interrupt(); Stop(); } void CConnman::SetServices(const CService &addr, ServiceFlags nServices) { addrman.SetServices(addr, nServices); } void CConnman::MarkAddressGood(const CAddress &addr) { addrman.Good(addr); } bool CConnman::AddNewAddresses(const std::vector &vAddr, const CAddress &addrFrom, int64_t nTimePenalty) { return addrman.Add(vAddr, addrFrom, nTimePenalty); } std::vector CConnman::GetAddresses(size_t max_addresses, size_t max_pct) { std::vector addresses = addrman.GetAddr(max_addresses, max_pct); if (m_banman) { addresses.erase(std::remove_if(addresses.begin(), addresses.end(), [this](const CAddress &addr) { return m_banman->IsDiscouraged( addr) || m_banman->IsBanned(addr); }), addresses.end()); } return addresses; } std::vector CConnman::GetAddresses(Network requestor_network, size_t max_addresses, size_t max_pct) { const auto current_time = GetTime(); if (m_addr_response_caches.find(requestor_network) == m_addr_response_caches.end() || m_addr_response_caches[requestor_network].m_update_addr_response < current_time) { m_addr_response_caches[requestor_network].m_addrs_response_cache = GetAddresses(max_addresses, max_pct); + + // Choosing a proper cache lifetime is a trade-off between the privacy + // leak minimization and the usefulness of ADDR responses to honest + // users. + // + // Longer cache lifetime makes it more difficult for an attacker to + // scrape enough AddrMan data to maliciously infer something useful. By + // the time an attacker scraped enough AddrMan records, most of the + // records should be old enough to not leak topology info by e.g. + // analyzing real-time changes in timestamps. + // + // It takes only several hundred requests to scrape everything from an + // AddrMan containing 100,000 nodes, so ~24 hours of cache lifetime + // indeed makes the data less inferable by the time most of it could be + // scraped (considering that timestamps are updated via ADDR + // self-announcements and when nodes communicate). We also should be + // robust to those attacks which may not require scraping *full* + // victim's AddrMan (because even several timestamps of the same handful + // of nodes may leak privacy). + // + // On the other hand, longer cache lifetime makes ADDR responses + // outdated and less useful for an honest requestor, e.g. if most nodes + // in the ADDR response are no longer active. + // + // However, the churn in the network is known to be rather low. Since we + // consider nodes to be "terrible" (see IsTerrible()) if the timestamps + // are older than 30 days, max. 24 hours of "penalty" due to cache + // shouldn't make any meaningful difference in terms of the freshness of + // the response. m_addr_response_caches[requestor_network].m_update_addr_response = current_time + std::chrono::hours(21) + GetRandMillis(std::chrono::hours(6)); } return m_addr_response_caches[requestor_network].m_addrs_response_cache; } bool CConnman::AddNode(const std::string &strNode) { LOCK(cs_vAddedNodes); for (const std::string &it : vAddedNodes) { if (strNode == it) { return false; } } vAddedNodes.push_back(strNode); return true; } bool CConnman::RemoveAddedNode(const std::string &strNode) { LOCK(cs_vAddedNodes); for (std::vector::iterator it = vAddedNodes.begin(); it != vAddedNodes.end(); ++it) { if (strNode == *it) { vAddedNodes.erase(it); return true; } } return false; } size_t CConnman::GetNodeCount(NumConnections flags) { LOCK(cs_vNodes); // Shortcut if we want total if (flags == CConnman::CONNECTIONS_ALL) { return vNodes.size(); } int nNum = 0; for (const auto &pnode : vNodes) { if (flags & (pnode->IsInboundConn() ? CONNECTIONS_IN : CONNECTIONS_OUT)) { nNum++; } } return nNum; } void CConnman::GetNodeStats(std::vector &vstats) { vstats.clear(); LOCK(cs_vNodes); vstats.reserve(vNodes.size()); for (CNode *pnode : vNodes) { vstats.emplace_back(); pnode->copyStats(vstats.back(), addrman.m_asmap); } } bool CConnman::DisconnectNode(const std::string &strNode) { LOCK(cs_vNodes); if (CNode *pnode = FindNode(strNode)) { pnode->fDisconnect = true; return true; } return false; } bool CConnman::DisconnectNode(const CSubNet &subnet) { bool disconnected = false; LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (subnet.Match(pnode->addr)) { pnode->fDisconnect = true; disconnected = true; } } return disconnected; } bool CConnman::DisconnectNode(const CNetAddr &addr) { return DisconnectNode(CSubNet(addr)); } bool CConnman::DisconnectNode(NodeId id) { LOCK(cs_vNodes); for (CNode *pnode : vNodes) { if (id == pnode->GetId()) { pnode->fDisconnect = true; return true; } } return false; } void CConnman::RecordBytesRecv(uint64_t bytes) { LOCK(cs_totalBytesRecv); nTotalBytesRecv += bytes; } void CConnman::RecordBytesSent(uint64_t bytes) { LOCK(cs_totalBytesSent); nTotalBytesSent += bytes; uint64_t now = GetTime(); if (nMaxOutboundCycleStartTime + nMaxOutboundTimeframe < now) { // timeframe expired, reset cycle nMaxOutboundCycleStartTime = now; nMaxOutboundTotalBytesSentInCycle = 0; } // TODO, exclude peers with download permission nMaxOutboundTotalBytesSentInCycle += bytes; } void CConnman::SetMaxOutboundTarget(uint64_t limit) { LOCK(cs_totalBytesSent); nMaxOutboundLimit = limit; } uint64_t CConnman::GetMaxOutboundTarget() { LOCK(cs_totalBytesSent); return nMaxOutboundLimit; } uint64_t CConnman::GetMaxOutboundTimeframe() { LOCK(cs_totalBytesSent); return nMaxOutboundTimeframe; } uint64_t CConnman::GetMaxOutboundTimeLeftInCycle() { LOCK(cs_totalBytesSent); if (nMaxOutboundLimit == 0) { return 0; } if (nMaxOutboundCycleStartTime == 0) { return nMaxOutboundTimeframe; } uint64_t cycleEndTime = nMaxOutboundCycleStartTime + nMaxOutboundTimeframe; uint64_t now = GetTime(); return (cycleEndTime < now) ? 0 : cycleEndTime - GetTime(); } void CConnman::SetMaxOutboundTimeframe(uint64_t timeframe) { LOCK(cs_totalBytesSent); if (nMaxOutboundTimeframe != timeframe) { // reset measure-cycle in case of changing the timeframe. nMaxOutboundCycleStartTime = GetTime(); } nMaxOutboundTimeframe = timeframe; } bool CConnman::OutboundTargetReached(bool historicalBlockServingLimit) { LOCK(cs_totalBytesSent); if (nMaxOutboundLimit == 0) { return false; } if (historicalBlockServingLimit) { // keep a large enough buffer to at least relay each block once. uint64_t timeLeftInCycle = GetMaxOutboundTimeLeftInCycle(); uint64_t buffer = timeLeftInCycle / 600 * ONE_MEGABYTE; if (buffer >= nMaxOutboundLimit || nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit - buffer) { return true; } } else if (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit) { return true; } return false; } uint64_t CConnman::GetOutboundTargetBytesLeft() { LOCK(cs_totalBytesSent); if (nMaxOutboundLimit == 0) { return 0; } return (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit) ? 0 : nMaxOutboundLimit - nMaxOutboundTotalBytesSentInCycle; } uint64_t CConnman::GetTotalBytesRecv() { LOCK(cs_totalBytesRecv); return nTotalBytesRecv; } uint64_t CConnman::GetTotalBytesSent() { LOCK(cs_totalBytesSent); return nTotalBytesSent; } ServiceFlags CConnman::GetLocalServices() const { return nLocalServices; } void CConnman::SetBestHeight(int height) { nBestHeight.store(height, std::memory_order_release); } int CConnman::GetBestHeight() const { return nBestHeight.load(std::memory_order_acquire); } unsigned int CConnman::GetReceiveFloodSize() const { return nReceiveFloodSize; } void CNode::AvalancheState::invsPolled(uint32_t count) { invCounters += count; } void CNode::AvalancheState::invsVoted(uint32_t count) { invCounters += uint64_t(count) << 32; } void CNode::AvalancheState::updateAvailabilityScore() { LOCK(cs_statistics); uint64_t windowInvCounters = invCounters.exchange(0); double previousScore = availabilityScore; uint32_t polls = windowInvCounters & std::numeric_limits::max(); uint32_t votes = windowInvCounters >> 32; availabilityScore = AVALANCHE_STATISTICS_DECAY_FACTOR * (2 * votes - polls) + (1. - AVALANCHE_STATISTICS_DECAY_FACTOR) * previousScore; } double CNode::AvalancheState::getAvailabilityScore() const { // The score is set atomically so there is no need to lock the statistics // when reading. return availabilityScore; } CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, uint64_t nLocalExtraEntropyIn, const CAddress &addrBindIn, const std::string &addrNameIn, ConnectionType conn_type_in) : nTimeConnected(GetSystemTimeInSeconds()), addr(addrIn), addrBind(addrBindIn), nKeyedNetGroup(nKeyedNetGroupIn), // Don't relay addr messages to peers that we connect to as // block-relay-only peers (to prevent adversaries from inferring these // links from addr traffic). id(idIn), nLocalHostNonce(nLocalHostNonceIn), nLocalExtraEntropy(nLocalExtraEntropyIn), m_conn_type(conn_type_in), nLocalServices(nLocalServicesIn), nMyStartingHeight(nMyStartingHeightIn) { hSocket = hSocketIn; addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn; hashContinue = BlockHash(); if (conn_type_in != ConnectionType::BLOCK_RELAY) { m_tx_relay = std::make_unique(); } if (RelayAddrsWithConn()) { m_addr_known = std::make_unique(5000, 0.001); } // Don't relay proofs if avalanche is disabled if (isAvalancheEnabled(gArgs)) { m_proof_relay = std::make_unique(); } for (const std::string &msg : getAllNetMessageTypes()) { mapRecvBytesPerMsgCmd[msg] = 0; } mapRecvBytesPerMsgCmd[NET_MESSAGE_COMMAND_OTHER] = 0; if (fLogIPs) { LogPrint(BCLog::NET, "Added connection to %s peer=%d\n", addrName, id); } else { LogPrint(BCLog::NET, "Added connection peer=%d\n", id); } m_deserializer = std::make_unique( V1TransportDeserializer(GetConfig().GetChainParams().NetMagic(), SER_NETWORK, INIT_PROTO_VERSION)); m_serializer = std::make_unique(V1TransportSerializer()); } CNode::~CNode() { CloseSocket(hSocket); } bool CConnman::NodeFullyConnected(const CNode *pnode) { return pnode && pnode->fSuccessfullyConnected && !pnode->fDisconnect; } void CConnman::PushMessage(CNode *pnode, CSerializedNetMsg &&msg) { size_t nMessageSize = msg.data.size(); LogPrint(BCLog::NET, "sending %s (%d bytes) peer=%d\n", SanitizeString(msg.m_type), nMessageSize, pnode->GetId()); // make sure we use the appropriate network transport format std::vector serializedHeader; pnode->m_serializer->prepareForTransport(*config, msg, serializedHeader); size_t nTotalSize = nMessageSize + serializedHeader.size(); size_t nBytesSent = 0; { LOCK(pnode->cs_vSend); bool optimisticSend(pnode->vSendMsg.empty()); // log total amount of bytes per message type pnode->mapSendBytesPerMsgCmd[msg.m_type] += nTotalSize; pnode->nSendSize += nTotalSize; if (pnode->nSendSize > nSendBufferMaxSize) { pnode->fPauseSend = true; } pnode->vSendMsg.push_back(std::move(serializedHeader)); if (nMessageSize) { pnode->vSendMsg.push_back(std::move(msg.data)); } // If write queue empty, attempt "optimistic write" if (optimisticSend == true) { nBytesSent = SocketSendData(pnode); } } if (nBytesSent) { RecordBytesSent(nBytesSent); } } bool CConnman::ForNode(NodeId id, std::function func) { CNode *found = nullptr; LOCK(cs_vNodes); for (auto &&pnode : vNodes) { if (pnode->GetId() == id) { found = pnode; break; } } return found != nullptr && NodeFullyConnected(found) && func(found); } int64_t CConnman::PoissonNextSendInbound(int64_t now, int average_interval_seconds) { if (m_next_send_inv_to_incoming < now) { // If this function were called from multiple threads simultaneously // it would be possible that both update the next send variable, and // return a different result to their caller. This is not possible in // practice as only the net processing thread invokes this function. m_next_send_inv_to_incoming = PoissonNextSend(now, average_interval_seconds); } return m_next_send_inv_to_incoming; } int64_t PoissonNextSend(int64_t now, int average_interval_seconds) { return now + int64_t(log1p(GetRand(1ULL << 48) * -0.0000000000000035527136788 /* -1/2^48 */) * average_interval_seconds * -1000000.0 + 0.5); } CSipHasher CConnman::GetDeterministicRandomizer(uint64_t id) const { return CSipHasher(nSeed0, nSeed1).Write(id); } uint64_t CConnman::CalculateKeyedNetGroup(const CAddress &ad) const { std::vector vchNetGroup(ad.GetGroup(addrman.m_asmap)); return GetDeterministicRandomizer(RANDOMIZER_ID_NETGROUP) .Write(vchNetGroup.data(), vchNetGroup.size()) .Finalize(); } /** * This function convert MaxBlockSize from byte to * MB with a decimal precision one digit rounded down * E.g. * 1660000 -> 1.6 * 2010000 -> 2.0 * 1000000 -> 1.0 * 230000 -> 0.2 * 50000 -> 0.0 * * NB behavior for EB<1MB not standardized yet still * the function applies the same algo used for * EB greater or equal to 1MB */ std::string getSubVersionEB(uint64_t MaxBlockSize) { // Prepare EB string we are going to add to SubVer: // 1) translate from byte to MB and convert to string // 2) limit the EB string to the first decimal digit (floored) std::stringstream ebMBs; ebMBs << (MaxBlockSize / (ONE_MEGABYTE / 10)); std::string eb = ebMBs.str(); eb.insert(eb.size() - 1, ".", 1); if (eb.substr(0, 1) == ".") { eb = "0" + eb; } return eb; } std::string userAgent(const Config &config) { // format excessive blocksize value std::string eb = getSubVersionEB(config.GetMaxBlockSize()); std::vector uacomments; uacomments.push_back("EB" + eb); // Comments are checked for char compliance at startup, it is safe to add // them to the user agent string for (const std::string &cmt : gArgs.GetArgs("-uacomment")) { uacomments.push_back(cmt); } const std::string client_name = gArgs.GetArg("-uaclientname", CLIENT_NAME); const std::string client_version = gArgs.GetArg("-uaclientversion", FormatVersion(CLIENT_VERSION)); // Size compliance is checked at startup, it is safe to not check it again return FormatUserAgent(client_name, client_version, uacomments); }